The present disclosure relates to writing an index in a file system, and more specifically, to writing an index in a linear tape file system (LTFS).
LTFS is an open standard format which allows for files stored on a magnetic tape to be accessed similarly to files on a disk or flash drive. In accordance with the LTFS format, the tape is divided into two partitions: an index partition and a data partition. The index partition is generally configured to store metadata, such as file allocation information, and the data partition is configured to store the body of the data.
While the file allocation information in a LTFS index partition is frequently updated, data is always appended to the tape (which is called a sequential access device). When data is recorded in a partition, the associated allocation information is recorded at the end thereof (in the data partition). To prevent lengthy mount times while the rearmost information is read when a tape is mounted, LTFS calls for the index to be overwritten and recorded to the beginning portion of the index partition in response to unmounting the tape. This makes it possible to always read the most recent index data from the index partition when mounting the tape.